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GD350-055G-4， 

Application: asynchronous motor ordinary speed regulation

Fault phenomenon: output phase loss reported after running for a period of time. 

How to solve it?

Cause analysis: 

Check that there are no abnormalities in the motor and the cables connecting the VFD to the motor. Measure the abnormality of the VFD main circuit. Disassemble and inspect the W-phase plastic shell for melting and discoloration of the copper bars. Continuing the inspection, it was found that one screw of the W-phase copper bar was loose. 

Solution: 

Replace with new components IGBT, copper bars, and chassis. 

Improvement effect: Running normally.

GD20-7R5G-4

Application: polishing machine. 

Fault phenomenon: The VFD operation data displayed on the HMI is lagging and the response is slow. 

How to solve it?

Reason analysis: 
Sort out the on-site control logic: PLC reads the operation data of 3VFDs through 485 communication, and then sends it to the HMI for display.

Check that multiple 485 communication lines and motor cables are bundled together in the electrical cabinet. Check that the VFD is well grounded.

Solution: 

Organize the cables and keep the 485 communication cable away from the motor cable to prevent interference.

Optimize the carrier frequency P00.14 to reduce external interference caused by VFD. 

Install collision rings on communication cables to enhance the anti-interference ability of signal cables. 

Improvement effect: interference elimination, smooth data display on the HMI.

GD350-5RG-4

Application condition: Ordinary speed regulation of asynchronous motor.

Fault phenomenon: More than 20 GD350 products have a power between 4kW-90kW. During debugging, it was found that some VFDs occasionally communicate normally and occasionally disconnect. 

How to solve it?
Reason analysis: 

Check that the communication related parameters of the VFD are set correctly. The communication between the upper computer and a single VFD is normal. Check the wiring for all VFDs using a set of chrysanthemum connections. Check that the terminal resistance is normal and that the communication line shielding layer is grounded properly. 

Solution: 

Change more than 20 VFDs to three sets of chrysanthemum shaped connections.

 Improvement effect:

 Communication is normal and there are no further disconnections. 

GD800-16-2736-6-01 

Application condition: Ordinary speed regulation of mud pump. 

Fault phenomenon: The inverter unit reports overheating after running the motor for a period of time. 

How to solve it?

Reason analysis: 

Check that the current during operation is within the rated range. The external ventilation system of the VFD is normal, and the air conditioning is working properly. Upon inspection of the internal cooling fans of the unit, it was found that two of them were not rotating. Check that the fan power supply voltage is normal. 

Solution: Replace 2 fans.

Improvement effect: The unit temperature drops and the equipment works normally.                   

GD350-185G-4， 

Application condition: Speed regulation of synchronous motor powder selection machine. 

Fault phenomenon: There is abnormal noise and mechanical vibration from the motor during startup, which is reported as STo.

 How to solve it?

Cause analysis: 

Check that the motor parameter settings are correct. 

Check the synchronous motor magnetic pole detection P13.01=2, P13.06=80%. 

Observe that the current is unstable during operation.

Solution: 

Optimize P13.06 to eliminate motor abnormal noise at the moment of starting after 30%. 

Optimize the speed loop control parameters of P3 group. 

Improvement effect: 

smooth start stop and stable operation.

GD300-01A-315G-4 drives permanent magnet synchronous air compressor, fault phenomenon: STo or OV1 is reported when running to 120HZ. How to solve it?

Reason analysis: 

The motor has a power of 280kW, a rated frequency of 150HZ, and a rated current of 487A. When the new machine is tested and running at 150HZ, the load current of about 640A is significantly higher.

Solution: 

Check the balance of the three-phase output voltage and output current of the frequency converter. If the current measured by the clamp meter is consistent with the frequency converter display, it indicates that the hardware is normal.

Checked the oil circuit of the air compressor and found no mechanical abnormalities. Do autotuning of the motor parameters and optimize parameter P02.21 from 0.19 to 0.15 and P02.22 from 0.37 to 0.25. The maximum current during 150Hz operation is around 480A, and the operation is stable.

GD270-200-4, Asynchronous motor water pump Application, fault phenomenon: operation reports UV. How to solve it?

Reason analysis: 

1 The static measurement main circuit is intact and the power display is normal.
2. After starting the VFD, observe that the fan does not rotate.
3. I cannot hear the sound of the contactor when I have repeatedly powered off the VFD.
4. The resistance of the contactor coil measured is normal, and the main contact is normal.
5. After replacing the power board, the contactor still does not operate.
6. Unplug 2 fan plugs, and the DC contactor will operate normally after power on.

Solution: After replacing the fan, it runs normally under load.

GD200A-18G-4

Application condition: Ordinary speed regulation for asynchronous motor drying equipment. 

Fault phenomenon: The frequency of the VFD does not increase after operation and reports overload. How to solve it?

Check the fault record for 6.6Hz/51V/68.8A. The static measurement of the main circuit using a multimeter shows no abnormalities. The clamp meter measures the actual current and the VFD display is consistent. Checking parameter P04.01=10.

Solution: Optimize torque boost parameter P04.01=1. The torque boost parameter P04.01 should be adjusted appropriately according to the actual situation, not the larger the better.

 GD350A-800G-6, Crusher application, 2 sets of 800kW VFDs drive 2 sets of 630KW motors. After the VFD is debugged, the trial production stage often reports  overload OL2. How to solve it?

The crusher is an impact load, and the stones processed by the equipment are blasted fastly, the size of the stone particles varies, and the impact of the load is uncontrollable, the maximum instantaneous current of the machine monitoring reaches 1800A, and the VFD selection is too small. 

Solution: Amplify the power of the VFD and ensure stable operation after being put into use.